Alarm apparatus for temperature control



June 7, 1 A A M. o. SNEDIKER 0 ALARM APPARATUS FOR TEMPERATURE CONTROL Filed Aug. 13, 1936 fbvizon 0 Sneadier Patented June 1, 1938 I t 2 119 05.

UNITED STATES PATENT OFFICE ALARM APPARATUS FOR TEMPERATURE CONTROL Morton 0. Snediker, Chicago, Ill., assignor to The Powers Regulator Company, Chicago, 111., a corporation Illinois Application August 13, 1936, Serial No. 95,770

' 2 Claims. (Cl. 200-140) My invention relates to apparatus particularly 26a formed as a part of the band that carries intended for use in connection with hydrotherapy the indications serves to limit rotation of the nut treatments, in which it is imperative that a to less than one revolution. A stem 21 projects predetermined temperature be maintained. upwardly from the bellows through an axial 5 Usually in such cases a recording thermometer opening in the part 23, the stem bearing against is employed in order that a record may be rethe lower of a pair of circuitbreakers 28, 28.

tained showing the actual heat application in The circuit breakers or switches are of a type terms of duration and temperature. I am aware obtainable on the market in which a snap action that apparatus has been employed for indicatis secured by very slight movement of the mov- .I 0 ing high and low temperature limits, in the naable part; this structure is shown in U. S. Pat- .ture of audible or visible means, and the appa-- ent No. 1,960,020. Since the actual construcratus here proposed is designed for securing the tion of the switch forms no part of this invention, desired result with simplicity and certainty, insuch construction is not illustrated or described eluding therewith means for varying not only the herein. It is suflicient to say that the projecting 5 low temperature limit but the range of permissiportions 30, 3| of the buttons shown in Fig. 3 ble temperatures above said low limit. In the serve to actuate contact fingers 32, 33 to make construction disclosed the mechanism is adapted and break the circuit shown in said figure. In for usewith equal advantage in connection with the two circuits 33a, 32a, that are alternately other heat controlling or indicating devices. opened and closed,'I have indicated bells 34, .35,

The invention will be more readily underor I may, as. shown in the upper circuit, include stood by reference to the accompanying drawa light 36 in series with the bell. It will be ing, in which; understood that .while I have indicated only Fig. 1 is an elevation of apparatus such as alarm elements by means of which the operator contemplated, the said apparatus being assois i f e f tempe atu Conditions audibly ciated with a casing and mechanism of a recordor visibly, yet I may connect the circuit to valve '25 ing thermometer; actuating means either to replace or supple- Fig. 2 is an enlarged side elevation, partly in ment the alarm element, in which case the regusection, showing the alarm unit; and, lation will be efiected automatically.

Fig. 3 is a diagram of the wiring that may be The mechanism for determining the range, or, 5 used. 'in other words the high temperature limit, is

In the drawing I have shown a casing or housmounted on the upper bracket 22 and includes ing In for a recording thermometer, the'dial that a nut 31 having temperature range indicating would normally overlie the open side of the figures 38 thereon, the nut having a threaded housing being omitted. Within the housing and projection 39 operative through the bracket 22 5 indicated in dotted lines at H is suitable clock and provided with a spring-pressed pin llladaptwork for rotating the dial, while the arm-actuated to provide controllable friction to the turning ing apparatus comprises the bellows l2 and the of the nut. The band that carries the range link mechanism |3 by which the pen arm ll, indicating figure thereon likewise has a stop 30a, indicated in dotted lines, is moved. The bellows the same as the stop 26a. The nut and projec- 0 is actuated by means of pressure generated in a tion has an axialopening containing a spring 4| 40 bulb IS, a capillary tube It serving as the means bearing against a headed pin 42 acting as an of connection. A branch II from the capillary adjustable stop that projects beyond the lower tube enters a bellows I8 constituting the motor end of the threaded part 49 and registers with for the alarm unggbout to be described. the button .3l that projects from the casing of 5 The unit is can d in a frame I9 having three the switch 29. By rotating the nut 31 the spacbracket arms 20, 2|, 22, vertically spaced apart. ing of the .pin 42 above the button 3|, is con- The lower bracket 20 has a fixed stop 20a theretrolled. A light spring 43 serves to return the on and carries the bellows l8 while the intermecombined switches as the bellows contracts. It diate bracket 2| carries a threaded projection will be noted that the two switch casings 23, 23

0' 23 surrounded by a compression spring 24 that are joined by means of a plate 44, the rearwardly 5o bears at its lower end against the bellows I8 and projecting portion of which provides a bearing at its upper end against an adjusting nut 25. A for a pin 45 seated in the frame l9. Thus the flange depending from the nut carries temperaswitches are bodily moved or oscillated in unison.

ture indications 26 that represent the low limit As stated .the alarm apparatus. is preferably 5 of temperature to be controlled. A stop member mounted within the casing of a recording thermometer as shown, the apparatus being available for change only by gaining access to the space behind the dial and beneath the cover which may be locked.

The operation is as follows:

Assuming a prescription that requires water treatment for a specified number of hours, the temperature'to be maintained between 98 and 10% degrees F.; in that case the regulating nut 25 is turned to indicate the low temperature. of

98. Then the adjusting nut ill! is turned so that the figure 6 is indicated by the pointer; this being the range specified. So long as the water temperature remains within that range, the buttons 3t, 3t will remain in the position shown in Fig. 2; that is, with both circuits open. However, if the temperature drops to the low limit, the bellows it will contract allowing the spring l3 to swing the switch casing downward and to permit finger 33 actuated by the button 30 to close the circuit 3311, thus giving a warning to the operator. In casethe temperature rises to 104, which is the upper permissive limit, then the bellows l8 will raise the switches and permit finger 32 to close the circuit 3212. Thus whatever low limit or range is desired can readily be provided by setting of the instrument.

The pin d2 backed by the spring ii, is so arranged in order to avoid breakage in case of an enforced adjustment that is not otherwise permitted by the position of the parts.

While I have illustrated apparatus in which electric current is utilized as the motive power, it should be understood that I contemplate other forms of motive power, such for example as air under pressure. In that case valves would replace the described circuit breakers. It should be understood, therefore, that in the accompanying claims, I intend this construction to be placed on the terms used therein.

I claim:

1.,In combination, a frame providing a pair of spaced. stops, means for varying the distance between the stops, a pair of switches having actuating buttons registering with said stops, said switches and buttons being bodily movable in unison between the stops, a heat responsive element adapted to move said switches to close a circuit at predetermined variable high and low temperature limits.

2. In combination, a frame providing a pair of spaced stops, means for varying the distance between the stops, a pair of switches having actuating buttons registering with said stops, said switches being joined and pivoted for oscillation between said stops, and a heat responsive element adapted to move said. switches to close two separate circuits at predetermined high and low temperature limits.

MORTON Q. SNEDIKER. 

